arch/arm64/mm/dma-mapping.c

   1 /*
   2  * SWIOTLB-based DMA API implementation
   3  *
   4  * Copyright (C) 2012 ARM Ltd.
   5  * Author: Catalin Marinas <catalin.marinas@arm.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <linux/gfp.h>
  21 #include <linux/export.h>
  22 #include <linux/slab.h>
  23 #include <linux/genalloc.h>
  24 #include <linux/dma-mapping.h>
  25 #include <linux/dma-contiguous.h>
  26 #include <linux/vmalloc.h>
  27 #include <linux/swiotlb.h>
  28
  29 #include <asm/cacheflush.h>
  30
  31 struct dma_map_ops *dma_ops;
  32 EXPORT_SYMBOL(dma_ops);
  33
  34 static pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot,
  35                                  bool coherent)
  36 {
  37         if (!coherent || dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs))
  38                 return pgprot_writecombine(prot);
  39         return prot;
  40 }
  41
  42 static struct gen_pool *atomic_pool;
  43
  44 #define DEFAULT_DMA_COHERENT_POOL_SIZE  SZ_256K
  45 static size_t atomic_pool_size = DEFAULT_DMA_COHERENT_POOL_SIZE;
  46
  47 static int __init early_coherent_pool(char *p)
  48 {
  49         atomic_pool_size = memparse(p, &p);
  50         return 0;
  51 }
  52 early_param("coherent_pool", early_coherent_pool);
  53
  54 static void *__alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags)
  55 {
  56         unsigned long val;
  57         void *ptr = NULL;
  58
  59         if (!atomic_pool) {
  60                 WARN(1, "coherent pool not initialised!\n");
  61                 return NULL;
  62         }
  63
  64         val = gen_pool_alloc(atomic_pool, size);
  65         if (val) {
  66                 phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val);
  67
  68                 *ret_page = phys_to_page(phys);
  69                 ptr = (void *)val;
  70                 memset(ptr, 0, size);
  71         }
  72
  73         return ptr;
  74 }
  75
  76 static bool __in_atomic_pool(void *start, size_t size)
  77 {
  78         return addr_in_gen_pool(atomic_pool, (unsigned long)start, size);
  79 }
  80
  81 static int __free_from_pool(void *start, size_t size)
  82 {
  83         if (!__in_atomic_pool(start, size))
  84                 return 0;
  85
  86         gen_pool_free(atomic_pool, (unsigned long)start, size);
  87
  88         return 1;
  89 }
  90
  91 static void *__dma_alloc_coherent(struct device *dev, size_t size,
  92                                   dma_addr_t *dma_handle, gfp_t flags,
  93                                   struct dma_attrs *attrs)
  94 {
  95         if (dev == NULL) {
  96                 WARN_ONCE(1, "Use an actual device structure for DMA allocation\n");
  97                 return NULL;
  98         }
  99
 100         if (IS_ENABLED(CONFIG_ZONE_DMA) &&
 101             dev->coherent_dma_mask <= DMA_BIT_MASK(32))
 102                 flags |= GFP_DMA;
 103         if (IS_ENABLED(CONFIG_DMA_CMA) && (flags & __GFP_WAIT)) {
 104                 struct page *page;
 105                 void *addr;
 106
 107                 page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
 108                                                         get_order(size));
 109                 if (!page)
 110                         return NULL;
 111
 112                 *dma_handle = phys_to_dma(dev, page_to_phys(page));
 113                 addr = page_address(page);
 114                 memset(addr, 0, size);
 115                 return addr;
 116         } else {
 117                 return swiotlb_alloc_coherent(dev, size, dma_handle, flags);
 118         }
 119 }
 120
 121 static void __dma_free_coherent(struct device *dev, size_t size,
 122                                 void *vaddr, dma_addr_t dma_handle,
 123                                 struct dma_attrs *attrs)
 124 {
 125         bool freed;
 126         phys_addr_t paddr = dma_to_phys(dev, dma_handle);
 127
 128         if (dev == NULL) {
 129                 WARN_ONCE(1, "Use an actual device structure for DMA allocation\n");
 130                 return;
 131         }
 132
 133         freed = dma_release_from_contiguous(dev,
 134                                         phys_to_page(paddr),
 135                                         size >> PAGE_SHIFT);
 136         if (!freed)
 137                 swiotlb_free_coherent(dev, size, vaddr, dma_handle);
 138 }
 139
 140 static void *__dma_alloc(struct device *dev, size_t size,
 141                          dma_addr_t *dma_handle, gfp_t flags,
 142                          struct dma_attrs *attrs)
 143 {
 144         struct page *page;
 145         void *ptr, *coherent_ptr;
 146         bool coherent = is_device_dma_coherent(dev);
 147
 148         size = PAGE_ALIGN(size);
 149
 150         if (!coherent && !(flags & __GFP_WAIT)) {
 151                 struct page *page = NULL;
 152                 void *addr = __alloc_from_pool(size, &page, flags);
 153
 154                 if (addr)
 155                         *dma_handle = phys_to_dma(dev, page_to_phys(page));
 156
 157                 return addr;
 158         }
 159
 160         ptr = __dma_alloc_coherent(dev, size, dma_handle, flags, attrs);
 161         if (!ptr)
 162                 goto no_mem;
 163
 164         /* no need for non-cacheable mapping if coherent */
 165         if (coherent)
 166                 return ptr;
 167
 168         /* remove any dirty cache lines on the kernel alias */
 169         __dma_flush_range(ptr, ptr + size);
 170
 171         /* create a coherent mapping */
 172         page = virt_to_page(ptr);
 173         coherent_ptr = dma_common_contiguous_remap(page, size, VM_USERMAP,
 174                                 __get_dma_pgprot(attrs,
 175                                         __pgprot(PROT_NORMAL_NC), false),
 176                                         NULL);
 177         if (!coherent_ptr)
 178                 goto no_map;
 179
 180         return coherent_ptr;
 181
 182 no_map:
 183         __dma_free_coherent(dev, size, ptr, *dma_handle, attrs);
 184 no_mem:
 185         *dma_handle = DMA_ERROR_CODE;
 186         return NULL;
 187 }
 188
 189 static void __dma_free(struct device *dev, size_t size,
 190                        void *vaddr, dma_addr_t dma_handle,
 191                        struct dma_attrs *attrs)
 192 {
 193         void *swiotlb_addr = phys_to_virt(dma_to_phys(dev, dma_handle));
 194
 195         size = PAGE_ALIGN(size);
 196
 197         if (!is_device_dma_coherent(dev)) {
 198                 if (__free_from_pool(vaddr, size))
 199                         return;
 200                 vunmap(vaddr);
 201         }
 202         __dma_free_coherent(dev, size, swiotlb_addr, dma_handle, attrs);
 203 }
 204
 205 static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page,
 206                                      unsigned long offset, size_t size,
 207                                      enum dma_data_direction dir,
 208                                      struct dma_attrs *attrs)
 209 {
 210         dma_addr_t dev_addr;
 211
 212         dev_addr = swiotlb_map_page(dev, page, offset, size, dir, attrs);
 213         if (!is_device_dma_coherent(dev))
 214                 __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 215
 216         return dev_addr;
 217 }
 218
 219
 220 static void __swiotlb_unmap_page(struct device *dev, dma_addr_t dev_addr,
 221                                  size_t size, enum dma_data_direction dir,
 222                                  struct dma_attrs *attrs)
 223 {
 224         if (!is_device_dma_coherent(dev))
 225                 __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 226         swiotlb_unmap_page(dev, dev_addr, size, dir, attrs);
 227 }
 228
 229 static int __swiotlb_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
 230                                   int nelems, enum dma_data_direction dir,
 231                                   struct dma_attrs *attrs)
 232 {
 233         struct scatterlist *sg;
 234         int i, ret;
 235
 236         ret = swiotlb_map_sg_attrs(dev, sgl, nelems, dir, attrs);
 237         if (!is_device_dma_coherent(dev))
 238                 for_each_sg(sgl, sg, ret, i)
 239                         __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 240                                        sg->length, dir);
 241
 242         return ret;
 243 }
 244
 245 static void __swiotlb_unmap_sg_attrs(struct device *dev,
 246                                      struct scatterlist *sgl, int nelems,
 247                                      enum dma_data_direction dir,
 248                                      struct dma_attrs *attrs)
 249 {
 250         struct scatterlist *sg;
 251         int i;
 252
 253         if (!is_device_dma_coherent(dev))
 254                 for_each_sg(sgl, sg, nelems, i)
 255                         __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 256                                          sg->length, dir);
 257         swiotlb_unmap_sg_attrs(dev, sgl, nelems, dir, attrs);
 258 }
 259
 260 static void __swiotlb_sync_single_for_cpu(struct device *dev,
 261                                           dma_addr_t dev_addr, size_t size,
 262                                           enum dma_data_direction dir)
 263 {
 264         if (!is_device_dma_coherent(dev))
 265                 __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 266         swiotlb_sync_single_for_cpu(dev, dev_addr, size, dir);
 267 }
 268
 269 static void __swiotlb_sync_single_for_device(struct device *dev,
 270                                              dma_addr_t dev_addr, size_t size,
 271                                              enum dma_data_direction dir)
 272 {
 273         swiotlb_sync_single_for_device(dev, dev_addr, size, dir);
 274         if (!is_device_dma_coherent(dev))
 275                 __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 276 }
 277
 278 static void __swiotlb_sync_sg_for_cpu(struct device *dev,
 279                                       struct scatterlist *sgl, int nelems,
 280                                       enum dma_data_direction dir)
 281 {
 282         struct scatterlist *sg;
 283         int i;
 284
 285         if (!is_device_dma_coherent(dev))
 286                 for_each_sg(sgl, sg, nelems, i)
 287                         __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 288                                          sg->length, dir);
 289         swiotlb_sync_sg_for_cpu(dev, sgl, nelems, dir);
 290 }
 291
 292 static void __swiotlb_sync_sg_for_device(struct device *dev,
 293                                          struct scatterlist *sgl, int nelems,
 294                                          enum dma_data_direction dir)
 295 {
 296         struct scatterlist *sg;
 297         int i;
 298
 299         swiotlb_sync_sg_for_device(dev, sgl, nelems, dir);
 300         if (!is_device_dma_coherent(dev))
 301                 for_each_sg(sgl, sg, nelems, i)
 302                         __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 303                                        sg->length, dir);
 304 }
 305
 306 /* vma->vm_page_prot must be set appropriately before calling this function */
 307 static int __dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
 308                              void *cpu_addr, dma_addr_t dma_addr, size_t size)
 309 {
 310         int ret = -ENXIO;
 311         unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >>
 312                                         PAGE_SHIFT;
 313         unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
 314         unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT;
 315         unsigned long off = vma->vm_pgoff;
 316
 317         if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
 318                 return ret;
 319
 320         if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
 321                 ret = remap_pfn_range(vma, vma->vm_start,
 322                                       pfn + off,
 323                                       vma->vm_end - vma->vm_start,
 324                                       vma->vm_page_prot);
 325         }
 326
 327         return ret;
 328 }
 329
 330 static int __swiotlb_mmap(struct device *dev,
 331                           struct vm_area_struct *vma,
 332                           void *cpu_addr, dma_addr_t dma_addr, size_t size,
 333                           struct dma_attrs *attrs)
 334 {
 335         vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot,
 336                                              is_device_dma_coherent(dev));
 337         return __dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
 338 }
 339
 340 static struct dma_map_ops swiotlb_dma_ops = {
 341         .alloc = __dma_alloc,
 342         .free = __dma_free,
 343         .mmap = __swiotlb_mmap,
 344         .map_page = __swiotlb_map_page,
 345         .unmap_page = __swiotlb_unmap_page,
 346         .map_sg = __swiotlb_map_sg_attrs,
 347         .unmap_sg = __swiotlb_unmap_sg_attrs,
 348         .sync_single_for_cpu = __swiotlb_sync_single_for_cpu,
 349         .sync_single_for_device = __swiotlb_sync_single_for_device,
 350         .sync_sg_for_cpu = __swiotlb_sync_sg_for_cpu,
 351         .sync_sg_for_device = __swiotlb_sync_sg_for_device,
 352         .dma_supported = swiotlb_dma_supported,
 353         .mapping_error = swiotlb_dma_mapping_error,
 354 };
 355
 356 static int __init atomic_pool_init(void)
 357 {
 358         pgprot_t prot = __pgprot(PROT_NORMAL_NC);
 359         unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT;
 360         struct page *page;
 361         void *addr;
 362         unsigned int pool_size_order = get_order(atomic_pool_size);
 363
 364         if (dev_get_cma_area(NULL))
 365                 page = dma_alloc_from_contiguous(NULL, nr_pages,
 366                                                         pool_size_order);
 367         else
 368                 page = alloc_pages(GFP_DMA, pool_size_order);
 369
 370         if (page) {
 371                 int ret;
 372                 void *page_addr = page_address(page);
 373
 374                 memset(page_addr, 0, atomic_pool_size);
 375                 __dma_flush_range(page_addr, page_addr + atomic_pool_size);
 376
 377                 atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
 378                 if (!atomic_pool)
 379                         goto free_page;
 380
 381                 addr = dma_common_contiguous_remap(page, atomic_pool_size,
 382                                         VM_USERMAP, prot, atomic_pool_init);
 383
 384                 if (!addr)
 385                         goto destroy_genpool;
 386
 387                 ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr,
 388                                         page_to_phys(page),
 389                                         atomic_pool_size, -1);
 390                 if (ret)
 391                         goto remove_mapping;
 392
 393                 gen_pool_set_algo(atomic_pool,
 394                                   gen_pool_first_fit_order_align,
 395                                   (void *)PAGE_SHIFT);
 396
 397                 pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n",
 398                         atomic_pool_size / 1024);
 399                 return 0;
 400         }
 401         goto out;
 402
 403 remove_mapping:
 404         dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP);
 405 destroy_genpool:
 406         gen_pool_destroy(atomic_pool);
 407         atomic_pool = NULL;
 408 free_page:
 409         if (!dma_release_from_contiguous(NULL, page, nr_pages))
 410                 __free_pages(page, pool_size_order);
 411 out:
 412         pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
 413                 atomic_pool_size / 1024);
 414         return -ENOMEM;
 415 }
 416
 417 /********************************************
 418  * The following APIs are for dummy DMA ops *
 419  ********************************************/
 420
 421 static void *__dummy_alloc(struct device *dev, size_t size,
 422                            dma_addr_t *dma_handle, gfp_t flags,
 423                            struct dma_attrs *attrs)
 424 {
 425         return NULL;
 426 }
 427
 428 static void __dummy_free(struct device *dev, size_t size,
 429                          void *vaddr, dma_addr_t dma_handle,
 430                          struct dma_attrs *attrs)
 431 {
 432 }
 433
 434 static int __dummy_mmap(struct device *dev,
 435                         struct vm_area_struct *vma,
 436                         void *cpu_addr, dma_addr_t dma_addr, size_t size,
 437                         struct dma_attrs *attrs)
 438 {
 439         return -ENXIO;
 440 }
 441
 442 static dma_addr_t __dummy_map_page(struct device *dev, struct page *page,
 443                                    unsigned long offset, size_t size,
 444                                    enum dma_data_direction dir,
 445                                    struct dma_attrs *attrs)
 446 {
 447         return DMA_ERROR_CODE;
 448 }
 449
 450 static void __dummy_unmap_page(struct device *dev, dma_addr_t dev_addr,
 451                                size_t size, enum dma_data_direction dir,
 452                                struct dma_attrs *attrs)
 453 {
 454 }
 455
 456 static int __dummy_map_sg(struct device *dev, struct scatterlist *sgl,
 457                           int nelems, enum dma_data_direction dir,
 458                           struct dma_attrs *attrs)
 459 {
 460         return 0;
 461 }
 462
 463 static void __dummy_unmap_sg(struct device *dev,
 464                              struct scatterlist *sgl, int nelems,
 465                              enum dma_data_direction dir,
 466                              struct dma_attrs *attrs)
 467 {
 468 }
 469
 470 static void __dummy_sync_single(struct device *dev,
 471                                 dma_addr_t dev_addr, size_t size,
 472                                 enum dma_data_direction dir)
 473 {
 474 }
 475
 476 static void __dummy_sync_sg(struct device *dev,
 477                             struct scatterlist *sgl, int nelems,
 478                             enum dma_data_direction dir)
 479 {
 480 }
 481
 482 static int __dummy_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
 483 {
 484         return 1;
 485 }
 486
 487 static int __dummy_dma_supported(struct device *hwdev, u64 mask)
 488 {
 489         return 0;
 490 }
 491
 492 struct dma_map_ops dummy_dma_ops = {
 493         .alloc                  = __dummy_alloc,
 494         .free                   = __dummy_free,
 495         .mmap                   = __dummy_mmap,
 496         .map_page               = __dummy_map_page,
 497         .unmap_page             = __dummy_unmap_page,
 498         .map_sg                 = __dummy_map_sg,
 499         .unmap_sg               = __dummy_unmap_sg,
 500         .sync_single_for_cpu    = __dummy_sync_single,
 501         .sync_single_for_device = __dummy_sync_single,
 502         .sync_sg_for_cpu        = __dummy_sync_sg,
 503         .sync_sg_for_device     = __dummy_sync_sg,
 504         .mapping_error          = __dummy_mapping_error,
 505         .dma_supported          = __dummy_dma_supported,
 506 };
 507 EXPORT_SYMBOL(dummy_dma_ops);
 508
 509 static int __init arm64_dma_init(void)
 510 {
 511         int ret;
 512
 513         dma_ops = &swiotlb_dma_ops;
 514
 515         ret = atomic_pool_init();
 516
 517         return ret;
 518 }
 519 arch_initcall(arm64_dma_init);
 520
 521 #define PREALLOC_DMA_DEBUG_ENTRIES      4096
 522
 523 static int __init dma_debug_do_init(void)
 524 {
 525         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 526         return 0;
 527 }
 528 fs_initcall(dma_debug_do_init);